A known type of respiratory valve has a body member that is tubular and has connected, in axial alignment on opposite sides thereof, two tubular members for inhalation and exhalation, respectively. A conical enlargement of these latter tubular members, at their connecting ends with the body member, provides housings for the mounting and operation of two valve units, for inhalation and exhalation, through a breathing chamber formed in the body member. A tubular mouthpiece member is connected to the body member, perpendicular to the tubular inhalation-exhalation members. The valve units used in this respiratory valve are of a relatively sophisticated structure. They have rigid, flat disks mounted on the end of a short cylindrical tube provided with a fastening flange; the rigid disks are translated and supported by resilient helical strips, so that the gas circulation occurs radially, while by-passing the margins of the disks. This way of operating the valve units presents a relatively large pressure loss and turbulent gas circulation, both in inhalation and in exhalation, that may disturb the patient. On the other hand, the resilient helical strips that operate the translation of the disks in a narrow annular space, may easily lead to the disk being blocked. As a whole, the known valve units are much too sophisticated for their use.
Finally, there are known respiratory and similar devices, having respiratory valves with other structures, in which the connection of the inhalation and exhalation members to the body member presents a V configuration, perpendicular to the tubular mouthpiece member. Such a V shaped connection presents the advantage of a better positioning of the respiratory valve to avoid the destruction of the operating field.